Luminaires with automated and remotely controllable functionality are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs and other venues. A typical product will commonly provide control over the pan and tilt functions of the luminaire allowing the operator to control the direction the luminaire is pointing and thus the position of the light beam on the stage or in the studio. Typically this position control is done via control of the luminaire's position in two orthogonal rotational axes usually referred to as pan and tilt. Many products provide control over other parameters such as the intensity, color, focus, beam size, beam shape and beam pattern. The beam pattern is often provided by a stencil or slide called a gobo which may be a steel, aluminum or etched glass pattern. The products manufactured by Robe Show Lighting such as the ColorSpot 700E are typical of the art.
Such gobos are typically the size of the luminaire's optical aperture and systems may be provided to select between different gobos, often mounted on a wheel, or to rotate a gobo once selected. The optical systems of such luminaires may further include gobos, patterns or other optical effects which are larger than the optical aperture and may allow movement across or through the beam to produce effects such as rainfall or fire. Such devices are often termed animation wheels and may be included in addition to gobos so as to further modify the light beam.
FIG. 1 illustrates a multiparameter automated luminaire system 10. These systems commonly include a plurality of multiparameter automated luminaires 12 which typically each contain on-board a light source (not shown), light modulation devices, electric motors coupled to mechanical drives systems and control electronics (not shown). In addition to being connected to mains power either directly or through a power distribution system (not shown), each luminaire is connected is series or in parallel to data link 14 to one or more control desks 15. The luminaire system 10 is typically controlled by an operator through the control desk 15.
FIG. 2 illustrates a automated luminaire 12. A lamp 21 contains a light source 22 which emits light. The light is reflected and controlled by reflector 20 through an aperture or imaging gate 24 and through an animation wheel 25. The resultant light beam may be further constrained, shaped, colored and filtered by optical devices 26 which may include dichroic color filters, gobos, rotating gobos, framing shutters, effects glass and other optical devices well known in the art. The final output beam may be transmitted through output lenses 28 and 31 which may form a zoom lens system. The automated, or remote controlled, movement of the components identified above are controlled by onboard electronics and motor controllers 27 as well established in the art.
FIG. 3 illustrates a prior art gobo wheel 1 containing five gobos 3 and an open aperture. The wheel 1 may be rotated 5 such that any of the gobos 3 may be positioned across the optical aperture of the luminaire 4.
FIG. 4 illustrates a further prior art gobo wheel 6. In this version the gobos 8 are contained within carriers 2 that may be rotated through gears 8. The wheel may be rotated such that any of the gobo carriers 2 containing a gobo 8 are positioned across the optical aperture of the luminaire 7 and said selected gobo carrier 2 may then be rotated around the optical axis of the luminaire producing a dynamic effect in the output beam.
In both examples, to change gobos from a first gobo to a second, non-adjacent, gobo requires that the wheel be rotated through all the gobos in between the first and second gobos. It would be advantageous if a gobo system could change from a first gobo to any second gobo without having to pass through intermediate gobos.
In addition it would be advantageous if gobos larger than the optical aperture could be inserted and removed from the optical aperture in any position or orientation. It would further be advantageous if two serially mounted gobos could be inserted and removed from the optical aperture such that overlay and moiré effects could be created.